Environmental Studies of the Bhopal Plant Site

The Bhopal plant closed after the 1984 gas release and never resumed normal operations. The Indian Central Bureau of Investigation (CBI), the Indian courts and the Madhya Pradesh Pollution Control Board (MPPCB) closely monitored and controlled all activity at the site.

No steps were taken to remediate the site while the Bhopal disaster litigation was in progress. The CBI considered the MIC unit “evidence” in the criminal case and blocked access to it. However, after the global settlement, numerous environmental studies were conducted through the years, sponsored variously by the Madhya Pradesh State Government (MPSG), MPPCB, Union Carbide India Limited (UCIL), various other Indian governmental agencies, Indian environmental firms and non-governmental organizations (NGOs). These studies tried to determine the extent of any soil and groundwater contamination at the site, whether groundwater in neighboring areas was contaminated and, if so, what had caused it. An chronological overview of the various investigations follows.

1. NEERI 1990 Study -- Solar Evaporation Ponds
In 1989, after the global settlement, the MPSG sponsored a study by the National Environmental Engineering Research Institute (NEERI) to determine the extent of contamination in the area of the site's solar evaporation ponds (SEPs) and to propose a clean-up method.

The SEP area, covering 35 acres, is composed of three ponds: Ponds I and II were used in normal operations, while Pond III was used for emergency purposes. The ponds -- which included a special polyethylene sheet on the bottom and on all sides to prevent seepage into the soil -- were used to store neutralized liquid waste from the plant.

NEERI tested 93 wells in a 10-kilometer radius of the ponds, including 11 test wells and 82 public drinking wells and concluded that:

  • The water in all was within drinking water standards;
  • The soil within 2.5 km of the solar evaporation ponds was not contaminated by the ponds;
  • There were very low concentrations of heavy metals in the ponds. The toxicity of the ponds was due to salts, not to organics;
  • Despite five monsoons following the disaster, there had been no leaching from the ponds. The polyethylene liner acted as a barrier together with the low hydraulic conductivity of the dense clay soil, and
  • Crop yield data for the area was better than the all-India average yield, which showed that UCIL operations had no adverse effect on crop growth.

NEERI found localized contamination of wells near the following locations:

  • Ice factory a kilometer south, southeast of the plant caused by calcium and sodium chloride used at the factory;
  • Central Warehouse located by a dumpsite; and
  • Gully, south, southeast of the plant.

NEERI recommended all the sediment, residue and contaminated soil be moved from Ponds I and II and placed it in a secure landfill in the area of Pond III.

2. NEERI’s 1992 Report -- Process Package for Disposal of Solar Evaporation Ponds Contents
This UCIL-sponsored study:

  • Found high levels of chloride in the SEP water despite eight monsoons since 1984, which strongly suggests the chloride contaminants were not leaching into the groundwater.
  • Monitored wells within two kilometers of the SEPs and found that they were of drinking water quality.
  • Concluded that the SEP area needed remediation, but the surrounding areas did not.

The remediation of the SEPs took place from 1995-1998 by Eveready Industries India Limited (the new name for UCIL) and was almost completed at the time the MPSG took control of the site in 1998. All of the work was done with the prior approval and under the close supervision of the MPPCB.

3. NEERI's 1997 Report -- Assessing Contamination at the Plant
In 1997, NEERI issued a 230-page assessment of the contaminated areas within the plant site. Developed with the assistance of Arthur D. Little, Inc., the report found contamination within the plant site, but found no groundwater contamination outside the site caused by the plant’s operations.

The report recommended that:

  • Contaminated soil and dump materials be excavated immediately on a priority basis to prevent further contamination of soil. It noted that the groundwater in the vicinity (within 500 meters) is potable, but a delay in implementing excavation may lead to its contamination.
  • The MPPCB expeditiously identify and approve a hazardous waste site where the excavated materials should be treated and disposed of in an environmentally friendly manner.

4. Indian Institute of Chemical Technology 1997 Report -- Disposal of Tarry Residues
The Indian Institute of Chemical Technology (IICT) also issued a report in 1997 concerning the best method for disposing of the Sevin and naphthol tar residues at the plant. The report analyzed a variety of treatment methods and concluded that a dedicated incinerator needed to be specifically fabricated to burn the waste due to the presence of a variety of hazardous residues. The report contained a proposal to the MPPCB for IICT to study the design of the proposed incinerator.

Turnover of the Plant to the Madhya Pradesh State Government -- July 1998


On July 7,1998, the MPSG revoked EIIL's lease and assumed control of the Bhopal plant site. Only the MIC and Sevin units and the administration building remained on the site at that time; the other units had been dismantled.

On July 28, 1998, the MPPCB publicly denied that there had been any water contamination caused by the operation of the plant and, in a press release, stated:

"The Madhya Pradesh Pollution Control Board collected and analyzed the samples from the tubewells and other drinking water sources in the areas around the Union Carbide premises early this month. The analysis found no traces of chemicals in the water sources that may be linked to the chemicals used in the Union Carbide factory or the wastes there. Samples from those water sources were also collected, water of which is non-potable. In these sources also no residues of such chemicals were found that may be linked to the chemicals used in Union Carbide or the wastes there....

"...National Environment Engineering Research Institute (NEERI), Nagpur, has collected and analyzed the samples from these water sources from time to time. In these analyses, no traces of chemicals were found that may be related to the chemicals used in Union Carbide factory....

"...It may also be mentioned here that three solar evaporation ponds were constructed for the treatment of contaminated water of the factory. The silt of pond number one and two has been safely disposed of in pond number three under the supervision of experts. This has been done through secure land fill technique suggested by the NEERI....

"...Recently, the Industries Department has taken possession of the entire 87.74 acres of land of Union Carbide by canceling the lease. After possession of the land by the State Government, the civil and criminal liabilities of Union Carbide will remain unchanged. The State Government will ensure safe disposal of the residual Sevin and naphthol tar from the factory. This will be done in consultation with NEERI, Nagpur, and I.I.C.T. Hyderabad."

Studies After 1998

Although UCIL had no involvement with the plant after the state government took over the site in 1998, and UCC never owned or controlled the plant site, UCC is aware of several other post-1998 investigations of pollution at the plant site. A brief description of these materials is included below.

5. Greenpeace 1999 Report
In 1999, the NGO Greenpeace (GP) issued a report that discussed samples of solid wastes, soil and groundwater from within the plant site and the surrounding area collected by GP in 1999 and analyzed at laboratories in Exeter, U.K.

All of GP’s samples were taken from areas where chemical wastes were stored or buried. It found contamination within the plant site and its “immediate surroundings.”

  • Well-Water Samples and Results
  • GP took 12 duplicate sets of well water samples -- one set from inside the plant site and 11 from the surrounding communities (known as locally as "colonies"). Of the 12 samples:

    -- 7 were negative; that is, not contaminated. They included three wells near the solar evaporation ponds, three south of the plant and one north of the plant. Five tested positive -- one from a bore hold at the plant site; one south of the plant; and three from wells in the immediate vicinity of Disposal Area I.

The conclusions of the Greenpeace report were similar to NEERI’s conclusions: there is hazardous waste within the plant walls that needs to be remediated and there is no real evidence that the groundwater outside the plant, except in the immediate vicinity of Disposal Area I.

1999 Greenpeace Report and the Bano Case in the U.S.


The GP report gives “special thanks” for the assistance of the Bhopal Group for Information and Action and Bhopal Gas Peedit Mahila Udyog Sanghatan, which actively participated in the investigation leading to the report. These two organizations also were plaintiffs in the Bano U.S. court case. The case was ultimately dismissed in favor of UCC, and the dismissal was upheld on appeal.

The claim of the plaintiffs in that litigation of widespread contamination in 16 colonies outside the plant site, was not supported by the GP report:

-- No testing was done in 10 of the colonies included in the lawsuit -- Annu Nagar, Garib Nagar, Chanbadi,Timber Market, Prem Nagar, Shri Ram Colony, Shiv Nagar, Sundar Nagar, New Arif Nagar, Preet Nagar and Kanchi Chola;

-- Testing was negative in 3 of the colonies -- Nawab Colony, Blue Moon Colony and Shiv Shakti Nagar;

-- Testing in J.P. Nagar colony was equivocal, with positive and negative results; and

-- Testing was positive only in Atal Ayub Nagar colony.

6. Srishti 2000 Report
This report by Shristi, a New Delhi-based scientific organization, acknowledges the contribution of Satinath Sarangi, who works with the Bhopal Group for Information and Action and other NGOs that have been intervenors or proposed intervenors in various Bhopal litigation cases. The reports discusses data as to contaminants found in breast milk – supplied by Mr. Sarangi – but does not explain how or where he obtained them. Shristi names seven off-site areas where it took well-water samples but, unlike NEERI, does not specify where they were taken, except to say that the sites were selected on the basis of their proximity to UCIL and dump sites near the plant.

7. Greenpeace 2002 Report
This report catalogs the type and location of chemical wastes within the plant site.

8. Indian National Institute of Occupational Health 2006 Report
In 2006, the Indian National Institute of Occupational Health (NIOH) issued a report that analyzed blood, soil and water samples taken in 2005 for organochlorine pesticides (such as DDT and hexachlorocyclohexane 3 [HCH]) and mercury and also for volatile organic compounds (VOCs) in water. The samples -- from 10 locations both near the plant site and at some distance from it, as well as from the plant site itself -- found no “abnormally high” values, with the exception of two isolated outliers – one soil sample within the plant site (mercury) and one just outside the plant boundary (HCH).

More specifically, NIOH reported the levels of:

  • Mercury in water and soil samples “were comparable with the levels of mercury reported from other parts of the country,” with the exception of one "high value" soil sample from inside the plant site.
  • DDT and HCH in water and soil samples from inside and outside of the plant site were “comparable”, with the exception of one soil sample from just outside the plant boundary that showed high levels of HCH. However, NIOH stated that the values of DDT and HCH found were less than the values of DDT and HCH reported in drinking water samples collected in 1990.
  • DDT, HCH and mercury in the blood of people residing in the 10 locations “are comparable with the levels of those compounds reported from other parts of the country.” NIOH found “no trend in the levels of pesticides in the blood with respect to the location of their residence from UCIL and the solar evaporation ponds.”

Finally, NIOH detected no VOCs in any water samples at a detection limit of 2 parts per million (ppm).

UCIL did not make DDT or HCH, but used DDT for mosquito control and mixed HCH with Sevin to make a pesticide called Sevidol.

9. Centre for Science and Environment 2009 Report
In its report, the Indian Centre for Science and Environment (CSE) concluded, based upon limited sampling, “that the land within the UCIL factory and waste disposal site is highly contaminated with pesticides, chlorinated benzenes and heavy metals.”

CSE also analyzed water samples from residential areas adjacent to the plant boundary and as far away as 3.5 kilometers. Although CSE broadly stated it found pesticides in the water samples above the limits set by the Bureau of Indian Standards, carbaryl pesticides and aldicarb (which could be associated with plant operations) were found in only four samples and in only one sample, respectively. The remaining contaminants (chlorinated benzenes and organochlorides) could have resulted from agricultural use. Moreover, the most contaminated sample – the only one to contain mercury above the standard – was the one furthest from the plant site.

10. NEERI 2010 Report
Commissioned by MPSG, the report delineates status of contamination in and around the plant site.

NEERI found:

  • That “excavation and recovery of dumped material from the dumpsites” on the main plant site, identified by NEERI's 1997 report and which had been “carried out by MPPCB” through a contractor in 2005, “is still incomplete.”
  • Conducted further monitoring of the groundwater from borewells on site and nearby existing wells and concluded that “groundwater in general is not contaminated due to seepage of contaminants from the UCIL dumps.”
  • “Isolated contamination” in five wells in the “immediate vicinity” of the plant site (to the east and north-east) was attributed "…to surface runoff from the dumps.”
  • Wastewater on the plant site from hutments and adjacent industries.
  • “Most of the plant, machineries and buildings” remaining on the site “are in dilapidated conditions and appeared to be contaminated.”

With respect to the content of the former solar evaporation ponds, for which a secure landfill had been created by UCIL/EIIL pursuant to NEERI’s recommendation, NEERI found that both the SEPs and landfill had been managed improperly and abandoned by the MPSG. The area was unguarded, littered with domestic refuse and the polyethylene liners used to prevent seepage from the SEPs and secure landfill had been “damaged” or “removed,” presumably by individuals living nearby. For the first time, NEERI found the soil around the SEP area to be contaminated.

NEERI recommended both immediate and long term remedial measures be undertaken. The immediate measures recommended were:

  • Proper fencing and security to UCIL premises and SEP area to prevent unauthorized access and use of these areas by public.
  • Immediate sealing of five contaminated wells to prevent use of water from these wells for any purpose by the residents.
  • Excavation and recovery of dumps materials. The incinerable wastes should be disposed off in the Treatment, Storage and Disposal Facility (TSDF) at Pithampur. The non-incinerable wastes to be disposed off in an on-site secured landfill facility to be constructed at UCIL.
  • Decontamination and decommissioning of plant, machineries and buildings prior to remediation of contaminated soil and groundwater.

Long-term measures addressed “remediation of contaminated soil and groundwater.” For contaminated soil, NEERI recommended “an on-site secured landfill facility. "For contaminated groundwater, a “pump-and-treat system was recommended.”

Finally, NEERI recommended that the MPSG “engage competent professional contractors for detailed engineering, and execution of various remedial measures."

11. Council of Scientific & Industrial Research-Indian Institute of Toxicology Research Reports 2012
Water and groundwater samples were collected in September-December 2012 by the Indian Council of Scientific & Industrial Research-Indian Institute of Toxicology Research (CSIR-IITR). Although CSIR-IITR stated that contamination found “may be due to the past UCIL activities,” they could not rule out that pesticide (organics) contamination resulted from agricultural usage. They also concluded that the presence of inorganics “have no relation with past UCIL activity.”

12. The Centre for Science and Environment Report of April 25-26, 2013, Expert Roundtable
The Indian Centre for Science and Environment (CSE) issued a report in June 2013 of an Expert Roundtable held in New Delhi on April 25-26, 2013. In addition to CSE representatives, attendees included representatives of the CPCB, IICT, NEERI, hazardous waste management companies, other experts and NGOs that have been involved in litigation over Bhopal (but no representative of the MPSG).

CSE presented an analysis of 15 studies conducted over the last 20 years to assess soil and groundwater contamination in and around the UCIL plant site and concluded that:

  • The studies reflect a consensus as to contamination of the soil at the plant site itself;
  • The contaminants found were similar and could be linked to process chemicals used and wastes generated by UCIL;
  • There is variation in reports of the nature and extent of groundwater contamination in surrounding areas, and
  • There were few studies of the waste stored at the site.

Based on the roundtable discussions, an action plan for immediate and medium- and long-term measures was proposed.

The immediate measures are:

  • Securing the site and preventing annual surface water runoff, including fencing and guarding the plant site and SEP area, stopping construction at the SEP area and preventing runoff of rainwater during the monsoon season into the neighboring areas.
  • Excavation, recovery and characterization of waste dumped at the UCIL site. The excavation of material from dump sites in 2005 was incomplete; new dump sites were discovered by NEERI in 2010 and further investigation to identify potential additional sites should be undertaken. Mercury present at the site should be collected in appropriate containers. The waste collected should be inventoried and characterized so proper means of remediation or disposal can be determined.
  • Characterization and incineration at Pithampur of the wastes previously collected.

The medium-and long-term measures are:

  • A thorough assessment of the type of contamination and its lateral spread around the site should be conducted because of differences and gaps in the previous study findings. Based on the results, a decontamination plan could be developed, including the technology options and magnitude of the remediation work.
  • Characterization of wastes in the landfill in the SEP area and development of a remediation plan. It was noted that the landfill was damaged and could be a source of groundwater contamination.
  • Assessment of the need to remediate the entire SEP area. It was noted that the area has not been satisfactorily studied.
  • Detoxification, dismantling and decommissioning of the remaining machinery and structures at the UCIL plant site.
  • Remediation and fate of the UCIL site. After completion of studies, a basket of appropriate decontamination/disposal methods should be developed, with a remediation plan to be chosen based on future use of the site as a memorial.

Time frames for each action were given, extending to five years for complete site remediation.